This invention relates to surface temperature measuring devices and more particularly to surface temperature measuring devices that are placed in contact with the surface whose temperature is to be measured.
In the measurement of the temperature of a surface by devices placed in contact with the surface, it is of utmost importance in order to obtain an accurate temperature measurement that the measuring probe not influence to any significant extent the thermal conditions existing in the surface. It is also, of course, desirable in most applications that the temperature measuring probe respond rapidly to the temperature of the surface. In some instances these measuring probe characteristics have been accomplished by including within the surface temperature measuring probe a heater so that the tip of the probe in contact with the surface is brought closer to the temperature of the surface being measured to reduce or eliminate heat loss from the surface by virtue of contact by the measuring probe. Typical examples of such surface temperature measuring probes utilizing measuring thermocouples are shown in U.S. Pat. No. 3,321,974Sterbutzel and U.S. Pat. No. 3,834,237Robertson. While such surface measurement probes reduce the heat drawn from the surface being measured and create an isothermal condition between the probe and the surface, there may be distortion in the thermal conditions of the surface whose temperature is to be measured because the normal heat loss from the surface due to radiation, convection, and conduction to the ambient conditions of the environment are essentially eliminated.
It is an object of this invention to produce a high speed, high accuracy surface temperature measuring probe having the characteristic that when placed in contact with the surface whose temperature is to be measured does not significantly alter the heat loss or heat transfer coefficient from the measured surface. This and other objects of the invention will be apparent from the following description.